Safety valve

Abstract

The invention concerns a safety valve, in particular for low pressures and aggressive media, with an inlet which ends at the top in a valve seat upon which lies in a sealing manner a weight-loaded sealing body. A certain overpressure below the valve seat and/or a certain underpressure above the valve seat causes the sealing body to lift. At its upper end, the sealing body forms a shaft projecting vertically upward which is guided along or in a vertical part fixed immovably to the valve body. Fastened along or on top of the shaft are two or more weights, particularly detachable weights.

What is claimed is:  
     
       1. A safety valve, in particular for low pressures and aggressive media, with an inlet ending at the top in a valve seat upon which lies in a sealing manner a weight-loaded sealing body, whereby a certain overpressure below the valve seat and/or a certain under pressure above the valve seat causes the sealing body to lift, characterized in that: 
       the sealing body forms at its upper end a shaft projecting vertically upward which is guided along or within a vertical part fixed immovably to the valve body, and that alone or on the shaft are fastened two or more detachable weights,  
       the upward projecting shaft comprises a vertical inner bore open at the upper end in which lies a rod fixed immovably to the valve body,  
       the rod is jacketed with a material resistant to aggressive media,  
       the shaft annular weights lie one above the other surrounding the shaft, and are jacketed with or consist of a material resistant to aggressive media, and  
       above the weights lies a disc, particularly of a material resistant to aggressive media, which is secured on the shaft by a round cord or a circlip.  
     
     
       2. A valve according to  claim 1 , characterized in that the outer side of the shaft comprises several annular grooves at intervals corresponding to the heights of the weights. 
     
     
       3. A valve according to  claim 1 , characterized in that the rod in the inner bore of the shaft contacts the said inner bore with only two annular projections. 
     
     
       4. A valve according to  claim 1 , further characterized in that an internal recess of the shaft is connected with the valve interior space via at least one venting bore. 
     
     
       5. A valve according to  claim 1 , characterized in that the sealing body comprises on its underside a recess, in particular a concave, conical edge, outside the valve seat.